
FUNCT IONAL BLOCK DIAGRAM
REV. A
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otherwise under any patent or patent rights of Analog Devices.
a
LC
2
MOS
m
P-Compatible 14-Bit DAC
AD7538
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
FEATURES
All Grades 14-Bit Monotonic Over the Full Temperature
Range
Low Cost 14-Bit Upgrade for 12-Bit Systems
14-Bit Parallel Load with Double Buffered Inputs
Small 24-Pin, 0.3
0
DIP and SOIC
Low Output Leakage (<20 nA) Over the Full
Temperature Range
APPLICATIONS
Microprocessor Based Control Systems
Digital Audio
Precision Servo Control
Control and Measurement in High Temperature
Environments
GE NE RAL DE SCRIPT ION
T he AD7538 is a 14-bit monolithic CMOS D/A converter
which uses laser trimmed thin-film resistors to achieve excellent
linearity.
T he DAC is loaded by a single 14-bit wide word using standard
Chip Select and Memory Write Logic. Double buffering, which
is optional using
LDAC
, allows simultaneous update in a sys-
tem containing multiple AD7538s.
A novel low leakage configuration (U.S. Patent No. 4,590,456)
enables the AD7538 to exhibit excellent output leakage current
characteristics over the specified temperature range.
T he AD7538 is manufactured using the Linear Compatible
CMOS (LC
2
MOS) process. It is speed compatible with most
microprocessors and accepts T T L or CMOS logic level inputs.
PRODUCT HIGHLIGHT S
1. Guaranteed Monotonicity
T he AD7538 is guaranteed monotonic to 14-bits over the
full temperature range for all grades.
2. Low Cost
T he AD7538, with its 14-bit dynamic range, affords a low
cost solution for 12-bit system upgrades.
3. Small Package Size
T he AD7538 is packaged in a small 24-pin, 0.3" DIP and a
24-pin SOIC.
4. Low Output Leakage
By tying V
SS
(Pin 24) to a negative voltage, it is possible to
achieve a low output leakage current at high temperatures.
5. Wide Power Supply T olerance
T he device operates on a +12 V to +15 V V
DD
, with a
±
5%
tolerance on this nominal figure. All specifications are
guaranteed over this range.